1. Field of the Invention
The present invention relates to a door closer, and more particularly to a door closer for a top hung sliding door that provides for efficient production and assembly.
2. Description of the Prior Arts
A sliding door opens by sliding, whereby a door panel is mounted on a track. Types of sliding doors include top hung sliding doors. The top hung sliding door has a door panel suspended from a track at a top edge and thereby the door panel can be easily moved. However, the door panel easily bumps against a doorframe if the door panel is slammed and that results in a big noise and causes the door panel or the doorframe to be damaged.
A door closer is mounted between the top edge of the door panel and the track to reduce the moving speed of the door panel and to keep the door panel and the doorframe from being damaged. A conventional door closer comprises a buffer mechanism and a trolley hanger. The buffer mechanism is secured to the track and includes a stationary base, a sliding block, a hook, two buffers and a resilient member. The sliding block is slidably mounted on the stationary base. The hook is pivotally mounted on the sliding block. The buffers are mounted on the stationary base and each buffer has a piston rod. The piston rod of one of said buffers abuts the sliding block and the piston rod of the other buffer abuts the trolley hanger. The resilient member is mounted on the stationary base and is secured to the sliding block at two ends. The trolley hanger is secured to the door panel, runs in the track and has an engaging recess selectively engaging the hook. When the door panel is opened, the trolley hanger drives the hook and the sliding block to slide relative to the stationary base and to pull the resilient member. When the door panel is closed, the buffers provide a buffering force and the resilient member releases a resilient force to reduce the moving speed of the door panel and to keep the door panel and the doorframe from being damaged.
However, the piston rods of the buffers must maintain an extended state to respectively abut the sliding block and the trolley hanger. Thus, a power device must be installed to drive the piston rods of the buffers to extend. This results in a high cost for the production of each door closer. Besides, because the piston rods of the buffers respectively abut the sliding block and the trolley hanger, travel distances of the piston rods are different. This then results in a difficult assembly process.
To overcome the shortcomings, the present invention provides a door closer for a top hung sliding door to mitigate or obviate the aforementioned problems.